The prominent components of halitosis are volatile sulfide compounds, especially hydrogen sulfide and methyl mercaptan, which can be produced by Helicobacter pylori(H.pylori). A possible relationship exists between H.pylori and halitosis from extraoral sources because bacterial eradication may resolve the symptom. However, the mechanism should be clarified. Gastroesophageal reflux disease is associated with halitosis, especially erosive cases. Almost 50% of dyspepsia patients develop halitosis, and the therapy of dyspepsia can lead to the disappearance of halitosis. However, this relationship remains unclear. Halitosis may be a significant concern in social situations because it is not only a health condition, but also has psychological effects that result in social and personal isolation. Given the undesirable condition of halitosis, the relationship between gastrointestinal diseases and halitosis should be investigated. Assistance should also be provided to the diagnosis and treatment of gastrointestinal diseases in relation to halitosis.
